Imaging systems today often include an array of pixel cells arranged in a predetermined number of columns and rows. Each of the pixel cells can be configured to sense an amount of light impinging on that pixel cell, and generate an appropriate signal corresponding to that amount of sensed light.
Generally, each pixel cell can include a number of metal lines coupled to that pixel cell, where control signals can be applied to these metal lines for controlling the operation of the pixel cell. For example, a pixel cell can include a reset (“RST”) metal line to which a RST control signal can be applied for resetting the pixel cell, a transfer (“TX”) metal line to which a TX control signal can be applied for transferring accumulated charges (e.g., accumulated by a photodiode) towards an output node, and a row select (“RS) metal line to which a RS signal can be applied to select a particular pixel cell's row for signal readout. Although this plurality of metal lines can be functional, the additional metal in the pixel array may detrimentally affect the imaging system. For example, the multiple lines of metal can take up room on the imaging die, thus reducing optical fill factor of the pixel and preventing at least some light going into silicon sensing area. Moreover, the multiple metal lines can increase metal coupling, thereby increasing noise, and reducing the conversion gain and the sensitivity of the imaging system.